Process and solution for the treatment of silx



industry is that known to the t Patentml sssa 3d, lldhtl mwmn, h Dfilltfikhl' EELS, NEW YORK, ASSIGNOE Til KIDWELL & SGH- PANY, 11336., A COBPURATION 0h NEW YORK ERQEEdfi MDSQLUTIQN EQR THE TREATMENT. 0h em I Ila This invention relates to a process for the treatment of silk generally, and also for the treatment of knitted silk articles such as hosiery, sweaters and the like. it applies also 5 to cotton. and other textile materials and to articles made therefrom.

While I consider my invention to he broadly new and while it has application either to silk or other textile material in theraw state,

a that is, in skeins or hanks before it has been made into the finished article, or to the article itself either alter or during the course or manufacture, T shall devote in self particularly in-this specification to a escription of e the process and the improvements derived from its use when applied to womens silk hosiery. Persons skilled in the art will readily be able to apply my invention to other articles or to silk, cotton, or other textile material in 0 its natural or raw state before it has been made up into articles.

There are a number of serious problems in the silk I hosiery industry. Many attempts have been made to solve them but so far as l 5 am aware no successful means has as yet been devised. @ne of the dificulties is that eom= monly known as picmng. Picking is the pulling out or tearing loose of threads in the stocking. This results from handling the e stockings and passing the fingers over their surface. When stockings are sold over the counter and handled by customers, a considerable number of them are rendered imperfect as a result of picking. The tiny loose strands of silk on the suriace'of the stocking make an almost imperceptible fuzz, and when the hand of the customer is passed over it certain of these strands are frequently caught and pulled loose. its a result the appearance-l oi the stocking is injured and them is a great tendency for a run to start at this point. My invention contemplates the prevention of this dificulty to a large degree.

Another common evilin the silk hosiery as sleazy to result knitting. Sleazy knitting is h from an inec uality oi tension hreads at dfierent portions t is articularly common s ave directly Application filed rel-war as was. semi in. estate.

silk. The smooth uniform appearance so desirable in silk stockings is seriously impaired by'sleazy knitting. According to my invention I treat stockings which are imperfect by reason of sleazy knitting and remove the undesirable surface appearance which it produces.

At the present time there is agreat vogue for sheer stockings. The process of my invention renders stockings more sheer and thus assists towards the end which the hosiery manufacturers are seeking without necessitating the use of diderent machines or finer grade silk. Also, I have found that stockings which have been subjected to the process of my invention take the dye more uniformly than untreated stockings. If, therefore my process is used before the stockings are dyed, this additional advantage can he made use of. v I

\ Tn practicing my invention, the'silk may he treated in the gum or alter the gum has heen boiledofi, but in either case the stocking must be dry before treating. The requirements of difi'erent manufactures will vary as to the time which it is desired to subject the stocking to my solution. Accordingly there will be a variation in the ingredients of the solution and of the amounts thereof, depending on the time of treatment. T have lound that a one-minute treatment is about right for most manufacturers, and the solu-' tion which I use in this case for Japanese mulberry silk is as follows:

99 hy vglume of 85%commercial formic am i by volume of 95% sulphuric acid (ojthe above volume) U. S. P. lycerine till quarter of an hour is very satisfactory. If it is desired to preserve the strength of the alkaline solution so that it may he used for a succession of such washings, the silk should be immersed in running water for tumor three minutes, or agitated in two or three still baths of water before it is transferred. to the alkaline bath. A good deal of the acid is thus washed out before the alkaline bath is given.

After this treatment the stockings are thoroughly washed in water after which they may be dried or, if the treatment is applied in the course of manufacture, they may be sent in a wet condition to the next step in the manufacturing processs. H the stockings are treated in the gum, they may be sent while still wet to the vats where the gum will be boiledoil, after which they will be dyed.

It will be understood that the percentage given above and. the specified strengths of the ingredients are not fixed but may be varied. somewhat under difierent conditions of treatment and for different kinds and grades of silk. For exam le, if it is desired to treat the stockin s on y a very short time, say hiteen seconds or less, it is not necessary to use glycerine or other protective a 'ents in the solution. But when treatments oi greater length of time are desired, glycerine or some other alcohol such. as ethyl alcohol or other suitable protective agent should be used in an amount which will according to the time of treatment. auction of the protective agent is to protect the silk fiber, or other material, from any possible loss in tensile strength or ela nd also to remove any tendency or M to become harsh to the touch; As been said, for a one minute treatment a amount should be about 2 of the volume of the two other ingredients. For a :3 treatment 5% of glycerine is Good results have been obtain hi h as 15% glycerine.

he strength of the formic acid vary from about to 95%. In the solution above given formic acid is specified. l. have found that this gives very satisfactory results and is easily obtainable on the market. Acid of greater than con-cen 'ation is very ex ensive and dilficult to obtr -l llhile acids 0 somewhat less than 80% ncentration might give fair results, pa cularl if the temperature of the solution is raised, best results are obtained within the age given. The stren h of the sulphi 'ic av also be varied, ut for the conditions above specified, about 95% the best. Again, the props-rt L formic acid and sulphuric acid may be changed somewhat without los 0' he effectiveness of the treatment, l in general. there should be about he: I formic acid and about .5 to

phuric acid. I have secured reasonabl satisfactory results with as low as .1% su phuric acid, but in order to do so I used formic acid of concentration, and this is so 6X- pensive as to be prohibitive at the present time.

The actual effect of my treatment on the fibers is, in my opinion, the drawing up or contracting or shrinking of the individual strands and particularly the projecting ends of the fibers that make up those strands. The surfacecondition of the silk is quite materially changed. It is smoother and firmer, there being little if any fuzz thereon. In the knitted stocking the treatment seems to act on the threads so as to equalize the tension thereon, and if the stocking contains sleazy knitting my treatment removes its characteristic irregular appearance. The smoothness of the treated fibers reduces in large measure the tendency towards picking, and the contraction of the strands and absence of the fuzz gives the stocking a thinner, more sheer appearance.

The process of my invention when properly applied should result in no weakening'of the fiber and no lessening of its elasticity nor that of the stockings as a whole. in fact, it has been my experience with stilk and cotton that the tensile strength and elasticity of the fibers have actually increased as a result of my treatment.

From the foregoing it will be seen that my invention is applicable not only to silk stockings but to silk, cotton and other textile materials in any of their many uses. And it will be further understood that substantial variations may be made in the solution and treatment herein described without departfroin the spirit and scope of my invention.

Vi hat l: claim is:

-. For the treatment o'l silk, a solution con- .iing formic acid and sulphuric acid, the ohuric acid content not exceeding 10% J olurne of the other ingredients.

For the treatment oi silk, a. solution which comprises not less than nine parts formic acid, not than one part sulphuric acid, a protective agent.

For the treatment of silk, a solution containing formic of not less than 80% concentration and sulphuric acid, the formic acid content being not less than 75% by volume of the entire solution.

a. For the treatmof silk, a solution containing formic acid of not less than 80% concentration, a protective agent such as glycerine, and concentrated sulphuric acid, the sulphuric acid content not exceeding 16% and the protective agent not exceeding 20% by volume of the entire solution.

5. For the treatment silk, a solution 'ch contains concentrated formic acid, and .entrated sulphuric in the proportion of between 98 to 2 and 995 to .5, respectively, and glycerine.

6. F or the treatment of silk, a solution which comprises about mi of 85% formic acid, about 1% of about 95% sulphuric acid, and glycerine in the amount of about 2 of the volume of the other ingredients.

7. T he method of treating silk which consists in subjecting it to the action of a solution containing formic acid and sulphuric acid, and then removing the acid.

8. The method 01% treating silk which consists in subjecting to the action of a solution containing concentrated formic acid, concentrated sulphuric acid and a protective agent and then washing the material in an alkaline bath.

9. The method of treating silk which consists in subjecting it for about one minute to the action of a solution containing not less than nine parts of to 100% formic acid, not more than one part oi concentrated sulphuric acid, and glycerine in the amount of about 2 of the volume of the two other ingredients, and then Washing the material in an ammonia hath.

10. The method of treating silk which consists in subjecting it for about one minute to the action of a solution containing about 99% of formic acid, about 1% of sulphuric acid, and glycerine in the amount of about 2%% of the volume of the other ingredients, then Washing the material for about fifteen minutes in a hath containing 3 to 5 per cent by Weight ammonia, and then washing it in Water.

11. For the treatment of silk, a solution containing a lower monobasic organic acid and sulphuric acid, the sulphuric acid content not exceeding 10% of the volume of the solution.

' CLEQ H. FIDWELL. 

